FanCoils Overview

7/27/2019 FanCoils Overview

1/6F1-24All Metric dimensions ( ) are soft conversion. Copyright Price Industries Limited 2011.Imperial dimensions are converted to metric and rounded to the nearest millimetre.

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Benefts o Using Fan Coil Units

Fan coils have been in use or decades as ameans o providing heating and cooling toindividual zones. The major advantages ousing an coil units are that they allow orlocal control o individual zones, reduce theamount o cross-contamination betweenzones and allow or hydronic heating andcooling.

Hydronic systems are ar more ecientthan all air systems because water pipingtakes up a raction o the space o ductwork.Fan coils can be selected to handle a zone'ssensible cooling load, signicantly reducingthe air fow requirements o the main air

handler needed or ventilation and latentloads only. This air fow reduction results ina smaller HVAC system which translates intoenergy savings. A smaller HVAC ootprintand duct system can also reduce foorheights or increase leasable space. Duringunoccupied hours the primary air systemcan be shut o to save energy while the ancoils maintain space temperature.

Construction

Compactunits reducedthefootprintof

the HVAC system and increase leasable

space

Heavydutyzinc-coatedsteelcasings

Unit casing's are internally lined with

dual density berglass insulation. The

insulation's high density skin provideserosion resistance while eectively

attenuating noise. Insulation meets

requirements o UL181 and NFPA-90A.

Several liner types are available to

address the issue o exposed berglass.

Removable access panels provide

access to the interior o the unit or

cleaning, inspection and service.

Three speed PSC motors allow for

reduced energy consumption

Perormance

Unit performance is AHRI certied

providing reassurance that design goals

will be met

Cataloged sound performance data isthe result o Price laboratory testing

done in accordance with industry test

standards.

Controls

Priceoffersavarietyof controloptions

to suit each application. Digital controls

are all actory calibrated, mounted and

wired to provide cost eective design

solutions

Quality Assurance

EachPriceFanCoil unit receives a full

operational check beore shipment and

arrives actory congured in accordance

with project specications. This means

costly labor and setup delays are

avoided.

UnitsareETLlistedtomeetUL1995and

CSA No. 236.

Outdoor Air

Relief Air

Zone 1

CLASSROOM

Zone 2

CLASSROOM

AHU

F

an

Coil

Unit

F

an

Coil

Unit

T T

Fan Coil Unit

Typical Fan Coil Layout

Overview

Fan Coils

Product Key

FC XX

Configuration

H - HorizontalV - Vertical

Model

C - ConcealedE - Exposed
http://www.price-hvac.com/Catalog/Section_F1/Fan_Coils_Horizontal/Overview.aspxhttp://www.price-hvac.com/Catalog/Section_F1/Fan_Coils_Horizontal/Overview.aspx


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Copyright Price Industries Limited 2011. All Metric dimensions ( ) are soft conversion .Imperial dimensions are converted to metric and rounded to the nearest millimetre. F1-25


Water Coil Selection Guide

Fan Coils

Fan Coils are typically sized to handle theheating or cooling load or an individualroom or zone. This load may be purelysensible or may have a latent portion. Therequired load should be calculated based onthe room occupancy, geographical locationand building construction.

Once the load is known, the entering airand water conditions or the coil must bedened. The entering air conditions will bebased on the space and the entering watertemperature will be based on the chiller.

To determine the approximate air fow othe required unit and thereore the unitsize, the rule o thumb o 375 cm / Ton orequired cooling (1Ton = 12000 BTHU/h) canbe used. This rule gives a starting point orselecting a an coil unit size. Units shouldbe selected near the midpoint o their fowrange. This will ensure that there is adequatean volume capacity or turn down i actualinstall system pressures are slightly higheror lower than the anticipated design. Thiswill also help lower the noise generated bythe an and allow or uture changes to thesystem. Selecting near the extremes o theoperating range should be avoided.

Next, the method o calculating coilperormance must be deined. Mostan coils are selected based on a 10 or12F temperature rise (based on chillerrequirements) but a set water fow rate(based on pump requirements) or a setleaving air temperature (or displacementventilation) may also be used.

Once all o these variables have beendetermined, the Price Fan Coil selectiontool can be used to calculate exact an coilperormance ratings. The number o coilrows and circuits can be adjusted to achievethe required capacity but there are pros andcons to changing each variable as shownbelow.

The air fow o the unit may also be adjustedto achieve the required capacity but careshould be taken when increasing the aifow o the unit as the generated noise andenergy use will also increase. Increasing theair fow will also aect the air distributionsystem and could lead to uncomortabledrats in the occupied space. In all cases, thevelocity across the coil should not exceed550 Feet per minute or condensate maycarry over rom the coil into the downstreamductwork. I a higher air fow is necessaryto meet the required capacity, a larger unisize should be considered to keep generatednoise and energy use to a minimum.

Heat Transer Air PD

Water PD

(or a given fow rate) Cost

Increase # o Rows

Increase # o Circuits

Sound Selection Procedure

The laboratory attained sound powerlevels or each unit at various an fows arepresented in the Acoustical Data tables.This data is derived in accordance withANSI/AHRI Standard 350 and shows theraw sound power levels o the an coil inthe 2nd through 8th octave bands with NOattenuation allowances.

The sound power levels include combinedradiated and discharge noise or unitsoperated at ree-delivery conditions withoutenclosures or ductwork. The sound powerlevels are useul or comparison purposesbetween unit size and manuacturer buthave limited value in determining theroom noise level. Contact our ApplicationEngineering group or assistance when thisis required.

Generally the an coil unit should be selectedat medium speed to reduce the noise level andprovide uture air fow adjustment fexibility.

To reduce noise rom urred in units, the ancoil should be mounted above a closet oradjacent space and ducted to a diuser witha short run o lined duct. Acoustically linedfex on the diuser connection will urtherreduce discharge sound rom entering thespace. A short section o lined duct on thereturn will also be benecial or inlet soundreduction. A ceiling with high transmissionloss will help reduce radiated sound.

Noise Reduction Design Considerations

Supply

Duct

Fan Coil Unit

Corridor

Return




PIC-FC

LINKER interface and softwarefor local setup

PCT-D and Linker Tool

Controls

Price oers actory mounted controlpackages or an coils to support standaloneand networkable solutions.

Basic Thermostats

The RAB, RCC and RDF thermostats areeconomical solutions or providing standalonecontrol to each an coil unit.

These thermostats eature a manual 3 speed answitch and are available or low voltage and linevoltage applications. Available options include:

2pipeand4pipeoperation.

Manualorautomaticchangeover.

Variousoperatingmodessuchaseconomy

and rost protection.Price Controlling Thermostat (PCT-D)

The PCT-D coupled with the Price Fan speedcontrol board (FC PSC3) provides simplestandalone control while oering a variety osequence options.The thermostat eatures adial adjustment and an occupancy button.The ollowing control sequence options aresupported by the PCT-D:

Automatic fanspeedadjustment (coupledwith the FC PSC3 Fan speed control board).

On/offormodulatingcontrolofwatervalves.

Automaticheat/coolchangeoverfor2pipeand 4 pipe systems.

Dischargeairtemperaturemonitoringof 4

pipe system. Nightsetbackwithoccupancyoverride.

Linker Device and Service Tool

The PCT-D comes pre-calibrated rom theactory; however, i eld adjustments arerequired, the Linker device gives the enduser this capability. Connecting to theservice port o the PCT-D thermostat, withthe aid o a laptop, the ree Linker Sotwarerom Prices website allows you to view themenus and change parameters within thePCT-D an coil controller.

Price Intelligent Controller forFan Coils (PIC-FC)

The PIC FC controller is designed specicallyor an coil applications oering maximum

fexibility and the ability or standalone ornetworked operation. A variety o inputs andoutputs allows coniguration o standardor complex control sequences includingvariable speed an fow, on/o or modulatingcontrol valves and discharge air temperaturecontrol. A range o thermostat options areavailable to suit the application including, LCD,motion sensor and wireless models. With theexception o wireless the thermostats connectwith ast and error proo RJ-45 cables. ThePIC FC architecture has a modular designwhich allows or a BACnet expansion module(PIC-BAC) to be added when connection to a

Fan Coils

Controls

Typical Fan Coil setup

Control Valve

Thermostat

Fan Coil Unit

T

Coil

central BAS system is required. The PIC-BACexpansion module can be actory installed,or connected in the eld via the ribbon cable.


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LCD Thermostats

BACnet Module

Price LINKER (Setup Tool)

Standalone LCD-SETUP

Fan Coils

PIC-FC Features

PIC Plug N Play

Wireless Thermostat LCD Thermostat withMotion Sensor

Flexible Thermostat Options

The PIC-FC has 5 thermostat options toft the buildings decor and architecturalrequirements all with a dierent rangeo unctionality.

BlankFaceThermostat

DialThermostat

LCDThermostat

LCDw/MotionThermostat

WirelessThermostat

Features and Benefts

The PIC-FC controls are designed andmanuactured in-house at Price, whichbrings many benefts when ordering a an

coil unit with Price controls. Controllersareprogrammedin-house

no delay on lead times.

Factory programmed with required

sequence and ready to go!

Easy RJ-45 connections to the

thermostat and the BACnet expansionmodule.

Pluggableterminalsfor inputs,outputs

and 24VAC power.

Customsequencesavailableuponrequest.

Easyeldadjustments.

The PIC-FC comes pre-calibrated rom theactory, however ield adjustments arepossible i required. There are several waysto access the setup variables in the PIC-FC.

1. Through the password protected menustructure built into the LCD thermostat.

2. Using the standalone setup tool: LCD-SETUP. It can be plugged into eitherthe Dial Thermostat or the RoomSensor Thermostat and used to setupthe controller when a computer is notavailable.

3. Through the service jack located on thebottom o each thermostat and the PriceLINKER device with a laptop

4. Through the BACnet network (orcontrollers ordered with the BACnetoption).

For more inormation on both the PriceControllingThermostat and PIC or Fan Coilsplease reer to Section G - Controls.

Setup o the PIC-FC




Variable Fan Flow

One o the key benets o the three speedan motor is the ability to operate at variablean fow during both cooling and heatingmodes. This provides exceptional roomtemperature control as well as energysavings.The ollowing is a control sequenceexample.

Cooling: On an increase in spacetemperature above the set-point, thecontroller opens the chilled water valve. Ispace temperature continues to increase,the controller will modulate the an speedto a higher air fow to maintain the roomset point.

Dead Band: With no demand in the space,the water valve actuator remains closed, Fanfow remains on low speed.

Heating:On a decrease in space temperaturebelow the set-point, the controller opensthe hot water valve. I space temperaturecontinues to decrease, the controller willmodulate the an speed to a higher air fowto maintain the room set point.

Automatic Heat-Cool Changeover

When 2 pipe systems are utilized the an coilcontrols can be selected to automaticallyswitch rom cooling to heating or vice versabased on the entering water temperature.This is accomplished with the additiono a actory supplied temperature sensor

eld applied to the water supply pipe. Theollowing is a control sequence example;

Chilled Water Supply: On an increase inspace temperature the controller opens thewater valve. I space temperature continuesto increase the an speed will modulate toa higher air fow. On a decrease in spacetemperature the controller modulates thean to minimum speed and nally closesthe water valve.

Dead Band: With no demand in the space,the water valve actuator remains closed. FanFlow remains at minimum speed.

Hot Water Supply:On a decrease in spacetemperature the controller opens the watervalve. I space temperature continues to

decrease the an speed will modulate toa higher air fow. On an increase in spacetemperature the controller modulates thean to minimum speed and nally closesthe water valve.

Dynamic Heat-Cool changeover: Iwater temperature will aid in the heatingor cooling o the space the controller willmodulate the water valve otherwise nomodulation will occur. (Eg. Space set-pointat 72 F and water temperature below set-point = cooling mode. Space set-point at 72F and water temperature above set-point =Heating mode).

3 Speed Fan FlowHeating ON Cooling ON

ON

OFF

High

Med

Low Low

Med

HighMax. Airflow

Min. Airflow

WarmCool Room Condition

RoomSet point

0.9F 0.9F

ValveSignal

Variable Fan Flow w/ Automatic Heat/Cool Changeover

Fan Coils

Typical Control Sequences


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Discharge Air Temperature Control

Both the PCT-D and the PIC-FC can besupplied with a discharge air temperature(DAT) sensor to maintain the discharge airtemperature o the an coil at a user denedset-point or both cooling and heatingoperation. During cooling the DAT controlcan be set at a temperature to maintainacceptable humidity in the space. Duringheating the DAT control can be set at atemperature to maintain acceptable roomair distribution and prevent stratication.The ollowing is a control sequence example;

Chilled Water Supply: On an increasein space temperature above the set-point,

the controller modulates the water valve tomaintain 55F discharge air temperature.This 55F is adjustable using the Linker USBsetup tool. I space temperature continuesto increase, the controller will increase thean fow and modulate the the water valve tomaintain the set discharge air temperature.

Hot Water Supply: On a decrease inspace temperature below the set-point,the controller modulates the water valveto maintain a discharge air temperature o90F. This 90F valve is adjustable using theLinker USB setup tool. I space temperaturecontinues to decrease, the controller willincrease the an fow and modulate the thewater valve to maintain the set dischargeair temperature.

Dead Band:With no demand in the space,the water valve actuator remains closed. Fanfow remains on low speed.

Discharge Air Temperature Control

3 Speed Fan FlowHeating ON Cooling ON

10 Volts

0 Volts

High

Med

Low Low

Med

HighMax. Airflow

Min. Airflow

WarmCool Room Condition

RoomSet point

1F 1F

ValveSignal

2F 2F

Heating%Co

oling

%

Valve modulates to maintainspace setpoint

Valve modulates to maintaindischarge setpoint

Fan Coils

Typical Control Sequences

Documents

FanCoils Overview